One type of electrophotographic color printer known in the art is a tandem-type color laser printer provided with a process cartridge for each of the toner colors yellow, magenta, cyan, and black. Each process cartridge includes a photosensitive member, and a developing roller for supplying toner to the photosensitive member.
A process cartridge detachably mountable in the body of such a tandem-type color laser printer is proposed. The process cartridge includes a drum unit provided with a photosensitive drum, and a developing unit provided with a developing roller and serving to accommodate toner.
The developing unit in this process cartridge is integrally provided with a developing device frame and a covering member. The developing unit is rotatably supported relative to the drum unit by a projected portion projecting from the developing device frame, and a cylindrical portion projecting from the covering member. The developing unit rotates relative to the drum unit about the projected portion and the cylindrical portion serving as the center of rotation. By rotating the developing unit relative to the drum unit, the developing roller separates from the photosensitive drum.